Nothing points to the difference between partial or zero gravity fields, and earth-normal (1 g) gravity, more than the question of liquid handling. On Earth, if a clinician wishes to sample a body liquid, such as blood serum, to analyze its analytes, such a person can pour the sample into an open cup and simply aspirate what is needed from the cup. In a space station, however, operating with less than or a total absence of, normal gravity, this will not work. First of all, liquid cannot be "poured". Even assuming it somehow finds its way into an open container, there is no reason for it to stay there. Any inertial effect on the container is likely to eject one or more globs of the liquid, to interfere with or contaminate the environment in which the analyzer exists. The logical "solution" to such a problem is to place a cap or cover over the cup or container, to retain the liquid. The difficulty with that is the open volume of the container under the cap will simply invite the liquid to disperse itself throughout the total container volume, leaving air bubbles in between the dispersed globs. Any attempt then to aspirate liquid from the container by inserting an aspirator through the cap, is likely to end up with the aspirator encountering air rather than liquid, or a combination of air and liquid.
Therefore, there has been a need, prior to this invention, for a container for body liquids to be used in combination with an aspirator, that will avoid the above-noted problems.
Liquid absorbing masses have been used in other containers, such as porous baffles to reduce slosh during operation and to prevent rapid release of fuel from a ruptured fuel tank of a racing car. However, these have not been associated with aspirators of body liquids, nor has there been any suggestion as to how they should be modified to allow them to be used with such aspirators in weightless environments.